New pc for old games

Hello, I’m putting together my 3rd pc I’ve built since 2004. I mainly use it for games. The oldest game I play is from 2002 (online) and the newest game I play is from 2015. Is the below build a fair rig?

NVIDIA GeForce RTX 3060 Corsair 4000D airflow cc9011200 Thermaltake tough power gf a3 1200 watt Western digital 1TB solids state drive sn770 m.2 2280 Corsair vengeance 64gb 288 pin ddr5 Asus tuff gaming z690 plus wifi lga 1700 atx mobo Intel core i7 12th gen alder lake 12 core lga 1700

I also have another question. I have 1200 watt power supply. Newegg estimated all my parts at about 620. Do I need A LOT more wattage, or would an 850 be just fine?